[HN Gopher] The international standard for identifying postal items
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The international standard for identifying postal items
Author : surprisetalk
Score : 105 points
Date : 2025-06-12 15:02 UTC (2 days ago)
(HTM) web link (www.akpain.net)
(TXT) w3m dump (www.akpain.net)
| Ecco wrote:
| With a limit of 10 million different serial numbers, I wonder how
| China does it. I can't come up with a decent estimate, and maybe
| I'm way off. But with the growth of sellers like Shein or Temu, I
| wouldn't be surprised if they shipped that many parcels in like a
| single day ? Or at least in a timeframe short enough that they
| would have over 10 million shipped but yet-to-be-delivered
| parcels, effectively running out of tracking numbers.
| xattt wrote:
| You could hate it by an internal metric, like date received.
| Scoundreller wrote:
| What helps is that they don't ship direct from China by mail
| much. They often send in bulk to the destination country and
| then mail locally, and local post systems can have their own
| domestic format.
|
| Or they have their own private courier do the last mile
| delivery too so it never touches any postal operator.
| bravesoul2 wrote:
| Do they? In Australia usually get them direct from HK or
| China because it is cheaper to do that even than post it
| within Australia!
| wombatpm wrote:
| Service type and serial need to be unique. Countries control
| what that 2letter field means. There is no rule against
| multiple codes indicating the same service. So AA through AZ
| would give you 260,000,000 unique combinations that you
| shouldn't reuse for 1 year. Rinse, later and repeat if you need
| more.
| mongol wrote:
| And I wonder what was the constraint to not make it longer when
| they developed the standard. Making it a few digits more seem
| it wouldn't cost much.
| omcnoe wrote:
| The cost will be in updating every legacy postal system that
| currently has fixed column lengths/input field length limits.
| topsecret wrote:
| Yes, now, but the person you're replying to was asking
| about at inception.
| Sharlin wrote:
| Yeah. Apparently last year they shipped over _two million_
| small parcels to Finland (pop. 5.6M) alone, which is completely
| bollocks.
| benced wrote:
| Even the US must easily run into this constraint.
| zinekeller wrote:
| > With a limit of 10 million different serial numbers, I wonder
| how China does it.
|
| The author has issued a correction, it's 100 million numbers
| per service indicator. But even then, it's probably not enough.
|
| The boring answer is that your shipping options are either get
| untracked postal service (which the S10 standard does not
| apply) or use a private courier (which also does not use the
| S10 standard).
|
| If you insist, you got two options for UPU-based postal
| tracking: normal e-commerce parcel aka H-codes, practically
| 2,300,000,000 trackable packages per year [1]. EMS is the other
| route, and there are another 2,300,000,000 trackable packages
| per year [2]. However, in my experience tracked postal delivery
| is only used in certain countries where it is more advantageous
| than private delivery (like until very recently in the US, for
| complicated reasons [3]), while other destinations has a more-
| than-willing private delivery partner (that is not the Big
| Three [4]) or even set up the delivery systems themselves.
|
| 1: 23 service indicators: HA-HW, HX-HZ are reserved for
| multilateral/bilateral use only
|
| 2: another 23 service indicators: EA-EW, EX-EZ are reserved for
| multilateral/bilateral use only
|
| 3: https://www.thewirechina.com/2020/11/22/delivering-chinas-
| ma...
| https://www.ft.com/content/a1233f3e-d21a-11e8-a9f2-7574db66b...
|
| 4: DHL, FedEx, and UPS
| somat wrote:
| Is the serial number even in base 10? the other parts of the
| number allow letters, the article does not say, but it could
| easily be base 36. which is close to 3 trillion serials.
|
| Plus a bonus rant: this is one of those things that looks like
| a number and as such you are tempted to use a number to store
| it, but its not, it's a string, you will never do math on it so
| it is not a number. see also: phone numbers, social security
| numbers, serial numbers.
|
| and sheepish bonus update: there is a checksum, so math is done
| on it. wonder if the checksum makes more or less sense in base
| 36? probably less, the checksum almost looks base12-ish, the
| mod(11), but there are special cases for two digit values so it
| is probably base 10.
| woooooo wrote:
| Eh, your comment here was checksummed several times as well
| crossing the network. Doesn't make it "a number".
| crtified wrote:
| The short answer is probably : in-house consolidation.
| forth_fool wrote:
| Isn't 8 digits closer to 100 million unique numbers than to 10?
| notpushkin wrote:
| It's _exactly_ 100 million unique numbers.
| akpa1 wrote:
| Author here - yep! It is, that was a typo in the article.
| mianm wrote:
| BTW, the correction in the post has the year as 2026 instead
| of 2025.
| akpa1 wrote:
| Ha, thanks for the heads up
| bloak wrote:
| Does that complex algorithm for the check digit have any
| advantage over the much simpler algorithm used for EANs or
| 13-digit ISBNs?
| nojs wrote:
| I'm surprised this article didn't mention the LPC code [1]
|
| 1. https://youtu.be/jPhXVrp0_oI
| ThePowerOfFuet wrote:
| Does anyone know what's going on with the DataMatrix code next to
| the address on some mail, such as periodicals such as magazines,
| which contains the full name and address of the recipient in what
| looks to be a standardized format with field separators?
| lysace wrote:
| I find some kind of solace in the 100% acceptance of some global
| standards. We can all agree on at at least some things.
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